As I've traveled around I have found about every area has a call maker or two. Some of them come up with some unique designs. Here is one a southern Ohio guy named George Huffman used to make. Any others out there, let's see some pictures. He called it a vibrating tongue, I killed some birds with it.

yes it takes chalk and needs a light sanding at times. Close to the hole is really course and the top of the tongue is higher pitch. It does great purrs with some practice of stiff pressure and pushing the striker.